Discovered the Front Driveshaft Out of Phase (Intentionally)

[BLtheP]

I have owned a 4th gen for a few months now and have been perusing the forums since they began. I've noticed quite a few people complain about vibrations in 4H, myself included. During the winter storm we got in January here in TX, I drove about 60 miles in 4H and it was quite an uncomfortable drive as I could feel the front driveshaft vibrating the entire way. Probably not ideal for bearings.

I initially chalked it up to Toyota maybe being lazy on the design of the front driveshaft angles, and deciding that with the ADD disconnecting things in 2WD, maybe they just don't care enough to solve the vibes since people live in 2WD most of the time.

I am in the midst of prepping for a regear, once 5.29 gears become available. Part of that is collecting differentials. I am contemplating a locker and thought it would be cool to delete the ADD at the same time, making for a more robust "fully live" front diff when the work is all said and done. However, because of the driveshaft vibrations, I can't really do that. Locking hub kits don't exist for this truck, so we're sort of stuck with the ADD.

Until....I climbed under the truck this evening to look at something else and noticed the front driveshaft was built out of phase.

For those who aren't aware, typically a standard 2-joint driveshaft has the two u-joints lined up so that they cancel each other out. this driveshaft is not that way, as you can see one photo has the u-joint basically perfectly flat (second photo) and the first photo the u-joint is rotated about 45 degrees.

This immediately piqued my curiosity, so I started looking at driveshafts on eBay. To my dismay, they are all like this! Even the hybrid trucks with the longer & beefier driveshaft (different looking design) have the same phasing mismatch. I have never seen anything like this. I cannot think of one reason why they would intentionally build them this way.

Here are some photos:



2024+ Tacoma non-hybrid

2024+ Tacoma Hybrid

2005-2015 V6 Auto & 2016-2023 V6 Manual

Notice how the 2024+ driveshafts have one u-joint sitting flat on the floor/table while the other one is rotated some? That is what I'm talking about. Notice how the 2005-2023 driveshaft has both u-joints sitting flat on the surface. That is how a 2-joint shaft is traditionally built.

So what say the rest of you? Is this why we have vibrations in 4WD? Can anyone smarter than me tell me why in the world Toyota would intentionally build 100,000-200,000 driveshafts per model year out of phase? Am I missing something? I have no doubt it's intentional since they are all like that, but....why? They didn't do that before on the previous generations. Did they incorrectly spec something that they just haven't discovered yet?

I did take a measurement of our front driveshaft (non-hybrid) and got a measurement of just under 29.5", which just about matches the 29.375" length of the 2005-2015 V6 auto and 2016-2023 V6 manual driveshaft shown above. I am tempted to try purchasing and installing one of those driveshafts and see what happens with vibrations. I am hopeful I can get it to where the front driveshaft can spin all the time with no issues. Currently, with the vibrations I get, it cannot.

Curious what the rest of you think.

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[BLtheP]

@JayTech Since you work at a dealer and have discussed driveshafts here quite a bit (albeit the rear, but still), any thoughts on this? Have you had anyone complaining about 4WD vibrations that were found to be the front and if so, any remedy to them?

 

[JayTech]

@JayTech Since you work at a dealer and have discussed driveshafts here quite a bit (albeit the rear, but still), any thoughts on this? Have you had anyone complaining about 4WD vibrations that were found to be the front and if so, any remedy to them?

Haven’t seen or heard anything about driveline vibrations related to the front shaft but I think there was an upcoming recall on front shafts made with incorrect materials or something so I’m not sure if maybe that would be related.

 

[Sagebrush]

So what say the rest of you? Is this why we have vibrations in 4WD?

In 23,000 miles and a fair amount of 4H on slick roads, I've never felt a vibration.

 

[BLtheP]

In 23,000 miles and a fair amount of 4H on slick roads, I've never felt a vibration.

How fast have you driven it in 4H? I have 4.30 gears and the vibes don't start until around 45 mph or so. Considering that logically, the 3.58 trucks wouldn't have the same condition until around 55 mph or so. And if you're riding around off-road, you may not notice, due to the terrain. On the road driving on ice/snow, it is absolutely noticeable and it is quite annoying and doesn't feel correct. All that aside, I understand how a driveshaft works and having the u-joints out of phase makes zero technical sense to me. I can't think of one reason why Toyota would have wanted to do it that way.

Just one example of a thread to the same effect: https://www.tacoma4g.com/forum/thre...ation-and-noise-when-in-4x4.8983/#post-113782

 

[Sagebrush]

How fast have you driven it in 4H?

At least 60.

 

[BLtheP]

At least 60.

Maybe you're lucky.

 

[Sagebrush]

Maybe you're lucky.

Have you talked to your dealer about this issue?

 

[BLtheP]

Have you talked to your dealer about this issue?

No. Not interested in that route.

 

[Sagebrush]

No. Not interested in that route.

I think you've made the assumption that it's supposed to vibrate. It isn't.

 

[BLtheP]

I think you've made the assumption that it's supposed to vibrate. It isn't.

It would be nice to keep the thread on topic, but I’ll bite.

Obviously I know it’s not supposed to vibrate, that’s precisely why I made the thread. Me not going to the dealer doesn’t mean I think it’s normal, it means I don’t expect them to fix it, and prefer not to waste my time on that option. At best they’d just set me up with another factory shaft built the exact same way.

The whole point here is the driveshaft itself. A standard 2-joint shaft is supposed to have the u-joints in phase so they cancel each other out. These clearly aren’t, and I’ve now seen multiple examples that all look the same across 4th gens.

There are also plenty of people reporting speed-dependent vibration in 4H, including me. Just because you haven’t noticed it doesn’t really prove anything—different gear ratios, speeds, and conditions all change when that vibration shows up.

So I ask again: why are these shafts built like this? From a driveline standpoint, it doesn’t make sense. Until someone can explain that with actual reasoning, I’m going to assume it’s not correct.

If anyone has a real technical explanation for the phasing, I’m all ears. Otherwise I’m going to keep digging into it.

 

[ORHV]

Maybe you're lucky.

Guess I’m lucky, too.

 

[BLtheP]

I’m focused on figuring out why some of these trucks clearly vibrate in 4H. Different setups (hybrid vs gas shaft length, gearing, etc.) aren’t really apples-to-apples, so sharing info about the ones that don’t have issues really doesn’t help much here.

If the thread doesn’t go anywhere with these constraints, I’ll probably just end up buying a driveshaft and test for myself.

 

[iron.head]

Subscribed to this thread and waiting to see the recall! Thank you!

 

[BLtheP]

Subscribed to this thread and waiting to see the recall! Thank you!

I don't think the recall mentioned above is related to this. Seems that one is for CV axles that can break and cause full time 4WD vehicles (Limited Hybrid) to roll away.

What issues are you having?

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